Product Description Description: Jacob’s Super Chuck Ball Bearing Drill Chuck is specifically engineered for heavy-duty, close tolerance production drilling. It is adaptable to a wide range of production drilling equipment, jig borers, milling machines, lathes and radials.  Utilizing a ball thrust bearing to reduce friction in the chuck closing mechanism, it permits the application of more gripping force on drill shanks to maximize drilling torque under the most demanding machining conditions Features: Strong Bit Holding Power Jaws Center-Grind For Straightness And Alignment Through-hardened Sleeve Teeth, Plus Hardened Nose And Keyholes Provide Outstanding Wear Resistance Jacobs’ Original Fluted Sleeve Design Design For Heavy Duty Industrial Applications T.I.R. 0.003″ Maximum At Half Capacity Specifications: Jacobs Catalog No. 30239 Maximum Capacity 1.000 in Minimum Capacity 0.375 in Mount 5JT Sleeve Outer Diameter 3.65 in Model Number 20N Packaging Boxed UPC: 095456302396 Enquiry Tell A Friend